The present invention is directed to a high yield process for producing dimetal sulfonyl amide salts which are highly useful as imidizing agents in the preparation of sulfonyl imides, which are in turn useful as strong acid catalysts, as electrolyte salts in electrochemical cells, and as monomers suitable for incorporation into ionomers. The products disclosed are useful in electrochemical applications such as batteries, fuel cells, electrolysis cells, ion exchange membranes, sensors and electrochemical capacitors.
Methods for imidizing chemical compositions containing sulfonyl fluorides particularly fluorinated sulfonyl fluorides are known in the art. For example, DesMarteau, U.S. Pat. No. 5,463,005, discloses substituted perfluoro-olefins of the formula 
where Xxe2x95x90CH or N, Zxe2x95x90H, K, Na, or Group I or II metal, R=one or more fluorocarbon groups including fluorocarbon ethers and/or sulfonyl groups and/or perfluoro non-oxy acid groups, Y=perfluoroalkyl or F, and m=0 or 1.
Xue, Ph.D. thesis, Clemson University, 1996, discloses the formation of the monomer
CF2xe2x95x90CFxe2x80x94OCF2CF2SO2N(Na)SO2CF3 
by reaction of CF2xe2x95x90CFxe2x80x94OCF2CF2SO2Cl with CF3SO2NHNa in the presence of Na2CO3 in acetonitrile
Further disclosed by Xue, op.cit,, is CF3SO2NNa2 made by reacting a mixture of CF3SO2NHNa and NaH in THF for four hours at room temperature. Xue""s CF3SO2NNa2 composition is reacted with a cyclic sulfone of the formula 
to produce the vinyl ether monomer, CF2xe2x95x90CFxe2x80x94OCF2CF2SO2N(Na)SO2CF3 at a yield of 4%, the remainder of the product being two saturated species, both present in larger quantities.
Behrend and Haas, J. Fluorine Chem. 4 (1974) 99-106, disclose the synthesis of CF3SO2NAg2 made from CF3SO2NAg2.NH3 at 200xc2x0 C. CF3SO2NAg2.NH3 is formed from CF3SO2NH2 and AgNO3 in aqueous solution while adding an aqueous solution of ammonia dropwise.
Meuxcex2doerffer et al, Chemiker Zeitung, 96. Jahrgang (1972) No. 10, 582-583 disclose a method for synthesizing RSO2NH2 where R is perfluoroalkyl.
The present invention is a composition comprising sulfonyl amide salts, of which at least 50 mol-% of said salts are dimetal sulfonyl amide salts represented by the formula
(RSO2NMb)3-bMxe2x80x2c xe2x80x83xe2x80x83(I) 
wherein R is aryl, fluoro-aryl, or XCF2xe2x80x94 where X is H, halogen, fluorinated or non-fluorinated linear or cyclic alkyl radicals having 1-10 carbon, optionally substituted by one or more ether oxygens, Mxe2x80x2 is an alkaline earth metal, b=1 or 2, c=0 or 1, M is alkaline earth or alkali metal when b is 1 or 2 respectively and c=0, and M is alkali metal when b=1 and c=1, with the proviso that c≢1 when b=2.
The present invention further provides for a process for forming a dimetal sulfonyl amide salt comprising:
contacting in an atmosphere having a water vapor concentration of less than 50 parts per million,
at least one alkali or alkaline earth hydride,
a sulfonyl amide or monometal sulfonyl amide salt thereof having the formula
(RSO2NH)3-aMxe2x80x3xe2x80x83xe2x80x83(II) 
wherein a=1 or 2, Mxe2x80x3 is alkaline earth metal when a=1, Mxe2x80x3 is alkali metal or hydrogen when a=2, and R is aryl, fluoro-aryl, or XCF2xe2x80x94 where X is H, halogen, or a fluorinated or non-fluorinated linear or cyclic alkyl radical having 1-10 carbons, optionally substituted by one or more ether oxygens;
and,
at least one aprotic liquid substantially free of water, thereby forming a reaction mixture; and,
reacting said reaction mixture forming a precipitate of (RSO2NMb)3-bMxe2x80x2c;
and separating said precipitate from said liquid.
As used herein, the term xe2x80x9creactingxe2x80x9d is intended to mean allowing at least two components in a reaction mixture to react to form at least one product. xe2x80x9cReactingxe2x80x9d may optionally include stirring and/or heating or cooling.